Hydraulic apparatus



Nov. 24, 1931. F. MOODY HYDRAULIC APPARATUS 2 Sheets-Sheet 1 Filed Aug.27,1927

IN VEN TOR Nov. 24, 1931. F. MOODY HYDRAULIC APPARATUS Filed Aug. 27,1927 2 Sheets-Sheet 2 514mm Laws F'- Mo QDY Patented Nov. 24, 1931 I "1l UNITED STATES PATENT OFFICE LEWIS FERRY MOODY, OF PHILADELPHIA,PENNSYLVANIA HYDRAULIC APPARATUS "10 the flow. These portions arecommonly near the entrance and discharge edges, and near the peripheryof the runner, although corrosion may and often does occur in otherportions of the blade. The corrosion is caused bythe setting-up of eddycurrents and disturbances of the flow, and the separation of .the waterfrom its guiding surface. Generally the pitting takes place on the backside of thev blade and works toward the front side or driving face,until as in some instances, holes have been made through the blade.

The object of this invention is to provide a.. turbine or pump structurein which the runner is formed with blades orvanes constructed in a novelmanner to control or redu e corrosion and pitting and in any event tocheck or prevent the pitting action from working beyond a certain point.

A further object is to provide a blade construction-which is adapted notonly to accomplish the above results but which will be strong, of lightweight, economical in manufacture and maintenance and efficient inoperation. Another object is to provide a run ner of built-up orcomposite construction,

composed partly of cast metal and partly of plate, with blades of thebest form for the hydraulic conditions of flow.

' Fig.1 is a plan view of one form of my improved runner partly brokenaway to show details of construction.

Fig; 2 is a side elevation of the runner shown partly in section.

Figs. 3, 4, and 5 are developed conical sections taken on theirrespective lines in Fig. 2,:eachof the sections being concentric to therunner axis as shown by lines 33, 4-4, and 5, 5 in Figs. 1 and 2, thesection line corresponding to line 33, Fig. 2, being omitted Applicationfiled August 27, 1927.

Serial No. 215,832.

from Fig. 1 for clearness. In Fig. 3 is also shown a view, normal to theblade, of the portion near the hub to show the connection between theblade and hub.

Fig. 6 is an enlarged sectional view taken on a meridian plane 6-6 ofFig. 1.

Fig. 7 is a combined fragmentary plan and a sectional View thereof, ofanother construction for joining the blade and hub.

Fig. 8 is an enlarged fragmentary section, 00

taken on lines 8-8 of Fig. 3.

Fig. 9 is an enlarged fragmentary section showing how the blade edgesmay be secured together.

Fig. 10is an enlarged fragmentary section 66 taken on line 1010 of Fig.7 I Fig. 11 is a bottom plan view of a modified form of runner embodyingthe principles of my invention.

Figs. 12, 13 and 14 are enlarged sectional views of various forms thatthe runner blade might take, all of said sections being taken on a linelocated similarly to the line 1212 of Fig. 11.

Fig. 15 is a vertical sect-ion showing a runner, of any of the forms, inthe cooperating structure of a hydraulic turbine.

Figs. 16and 17 are further modifications of a blade construction whichis generally shaped like those in Figs. 4 and 5.

My invention broadly contemplates the use of a runner having provisionfor supporting a fabricated blade and so arranging the elementsconstituting the blade that if operating conditions are conducive tocause pitting or corrosion, such may be effectively prevented, cheekedor controlled. In addition, the blade elements, a part or all of whichare preferably made of plate metal, are arranged so that a vane shape isobtained highly conducive to efiicient operation and conforming with themost advantageous flow conditions, and in addition the shape is such asto impart great strength to the blade.

In one specific aspect of the invention the blade is made not onlyextremely strong, considering its power capacity and the weight ofmaterial used, but the arrangement checks the extent of pitting action,if such should occur, by the provision of a relatively thus-formed theinterior-chamber 7.

large interior chamber within the blade so that it pitting action oncepenetrates some point of the chamber wall the destructive energy ofany'eddy currents or corroding conditions will be dissipated uponpassing into the chamber or space. In this way the opposite chamber wallwhich may form the driving face of the blade is relatively free from thecorroding conditions that it would be sub-.

jected to without the protection of the dissi-,

pating chamber or space.

To accomplish the above results the form shown in Figs. 1 to-6 the tourbladedrunner R has its hub 1 preferablyot cast metal, us

ually of cast steel or in some cases cast iron,

rovided-with tourinte' ral'lcast lu s 2. The P u e numberotbladesmay-beincreased or: de

creased, but "for runners'of the highspecific speed propellertype shownthe number will "usually be from three to SlX'OI at most eight.

Secured tothe-lugsare blades 3,-;which, in order-to forman-interiorchamber or space and also obtain great strength by utilizing principlesot-beam construction, are preterably madeof plate metahu'sually platesteel,

although the same can'be cast as a'single blade unit either of cast ironor steel. I

" In the case ot'apla-te metal blade the sameis formed preferably ofupper and lower plates land 5,"'prefe-rably Welded at-their edges as at6 and. suitably-shaped so as tobe conducive not only toefiicient'operat'ion and flow conditfions' but also to impart greatstrength to the blade, andby such a formation there 1s The blade asshownin Fig. Sis, adjacent the hub,

relatively deep in its middle portion and tapers more. gradually towardthe discharge edge a than it does toward the inlet edge 6,

the inlet edge being formed with'arel-atively Lebl-unt and roundedcontour. As conicalsections are taken on thefblade at'increasing'd'is-"tances from the-runner =aXis,' -it -iS seen from Figs; 4 and 5- thatthe blade not only approaches a morehorizontal position but also thedepth of the blade diminishes while the width thereof increases until aspartly shown inF ig, 5, the upper and lower plates come togetheradjacent-the tip and are suitably secured-preferably as by welding alongthe peripheral edge or tip.

' meridianfsections, the blade thus pre- 'sents a beam-like constructionwhich more specifically would be of theca ntilever type,

one such section being shown in 6. In

"order to add further strength to the blade without materiallyincreasing its weight, "a

'block or support {8 is interposed between the firont and back sides andsecured-thereto by rivets or sn r'table means such as welding, the

7 number of supports being varied orentirely omittedas isdeemedne'cessary in any given case.v 'i ThsectiOnshown infFig. -6 issubstanftiallythe same section shownbetweenthe pair of lines 11" inwhereas othersecn the l.

tions defined by the pairs of lines numbered 9, 10, 12 and 13 of Fig. 2are taken on meridian sections indicated in Fig. 1 with the same numbersunprimed. These sections also are indicated in Figs. 3 to 5 by similarnumhere. It will be noted in these latter figures that the sectionlines;9;.13 converge toward a pointon the lower sides of the'blades,this being due to the fact that said sectlons are simply conicalsections rolled out onto a plane and necessarily "the"meridianplanesindicated by lines 9 13 must all pass through the age of the cone. Ineach of the meridian sensindicfi/tedby the pairs of lines 913 in Fig. 2the dot and dash line indicatesthe curvature along the lower surface orback side of the blade-while the dotted lines indicate thecurvaturevalong the front or driving surface of the blades, itbeing-noted that n l-rile certain of these lines curve when con--sidering their entire length, yeta material-or 'major portion of each oftheselines is substantially straight, this being particularly true orthe face lines which are dotted, thereby causing substantially the majorportion or the blade surfaces to be formed of straight lugs 2 andsecured thereto either by rivets 15 or by providing holes in the platesand then welding to the lugs 2 through the holes as shown at16 in Figs;7 and 10'.

' In either case however the inner blade ehds at 16' thereby increasingtheir strength and ln g against any open spaces,"cracks or the whichmight be conducive to causing pitting or corroding. It will also beunderto conform to the entire inside contour-ofthe plates may only do sopartially but always of course to such an extent that sufficientstrength may be had.

In View of the fact that pitting .or corros'ion most generally occurs onthe lower'blade surface, it will be understood that the lower plates mayif desired be made of any special material which might be moreresista-ntto pit-ting than the material forming the upper plate or if desired bothplates mavbe made of special-material. In-any event, however, it will benoted that should pitting become so severe as to completely penetrate.;;the lower plate :5 the relatively large chamber :or space 1 will thenact as a means of protection pitting o f'the upper plate -4; by theconditions whichex ist-on the lower side of-the runner. One explanation;or this protecting" are preferably welded to the shoulder 14 as stoodthat the lugs 2 instead of being shaped of the blade the volume of suchspace will .be relatively large. It is also seen that due to the use ofthe relatively thin plates the same could readily be restored as bylocal welding or replacement to their full normal condition both as tostrength and contour.

If pitting once occurs in the applicants present type of runner blade,the pitting action will be arrested 'duefto the built up constructionpermitting the use of resistant material fabricated in plate form,together with the hollow space or dissipating chamber, and in that way,the hollow runner blade negatives the destructive conditions which areset up I by the elements forming the high specific speed installation.

A further feature of the construction shown is that due to the spacingof the plates the upper and lower plates will be positioned amaterialdistance from the neutral axis of the blade as a whole, it beingnoted that the strength of the blades are controlled in accordance withthe principles of beam construction. Inasmuch as it is the outermostfibers of any beam which must take the maximum stresses it is seen thatthe plates are placed at the most effective position to take the entireload, and inasmuch as the plates are preferably made of steel, havinghigh tensile and compressive strength, the same can 'be made relativelythin thereby providing not only a light weight runner but one which iseconomical in cost and very strong in resistance to both steady forcesand shocks.

While the blades may be made of any desired shape it will be noted fromFigs. 1 and 2that in the specific embodiment herein described the tot'alblade area is at least equal to the disc area bounded by circlescontaining the hub and the blade tips, while in meridian sections theblades on their upper surface tend toward or are slightly concave whilein developed conical sections the upper surfaces'of the plates areconvex and certain of said sections on their lower surface are at leastpartially concave although as shown in=Fig. 4, a considerable portion ofthe lower ed in operation. These inner portions 17 of the blade aresubstantially triangular in formation when viewed in a planeperpendicular to the axis, as shown in Fig. 11. The entrance anddischarge edges of the blades are composed of plate metal which willcarry the bending stresses to which the runner is subjected and resistthe corrosion of the blades at the edges. The plate metal sections 18and 19 are riveted, welded, or otherwise secured to the inner castsections 17. Countersunk rivets 20 are illustrated in Fig. 12 to producea smooth surface free from any irregularity which would disturb theflow, these rivets for simplicity being shown on only one of the bladesin Fig. 11. The inner cast sections 17 are cast with or subsequentlyformed with flanges 21, which if not so cast are formed by cuttin awaythe casting to suit the thickness of metal. The entrance section 19 ofplate metal is constructed either of one piece bent in somewhat U-shape,forming the front and back surfaces of the blade, or of two pieceswelded or riveted together and then secured to the flanges 21 of theinner cast section 17. The use of two plates will usually be preferableon account of greater ease in forming them. The discharge section 18 isformed of two pieces of plate metal tapered to a thin edge at dischargeand either welded or secured together by countersunk rivets 22, formingthe front and back surfaces of the blade. The discharge section isriveted to the lower flange 21 of the inner cast section. The platesections also may be welded to the cast section by providingperforations or holes to be filled by welded metal.

As shown in Fig. 12 the arrangement of the upper and lower plate membersforming the entrance and discharge portions of the blade is such thatthere is formed a chamber or space. similar to that shown in thepreferred form in Fig. 1. Due to securing the plates 18 and 19 at theirinner edges to the central portion 17 said plates are in the form of acantilever which is also generally true of similar plates shown in Fig.13 to be described.

In the form shown in Fig. 13 the member 24 corresponding broadly to thelug 17 has reduced portions adjacent the entrance and discharge edges,the reduction being of sufficient depth that plate metal members 25 arecontinuous with the surfaces of the central portion 24. The plates 25and portion 24 will be secured together either by rivets or welding andin any of the forms shown the edges of the blade members will bepreferably welded together.

In the form shown in Fig. 14 the body of the vane 26 is either partiallyor wholly encased or covered by plate metal members 27. These plates maybe made in a plurality of sections herein shown as two each for the theplate a frOiit'Eand backv sides of. the blade; The ad- 'ja-cent edges.of each set of'plates are secured by welding while the front and backplates adjacentthe entrance and dischargeedges arelikewise secured. byWelding. In case it should be deemed necessary, each of the bladeswherein a hollow interior. is used. could be provided with asmallopening. to allow free circulation'of fiu-id therein .and in that waythere is eliminatedany tendency. for the: runner to become unbalanced incasewater-should enter only one, or less than all, of'the interiorspaces through leakage orthe like.

.gle plate.

However,.the means for securing the plates including Welding or rivetingwould ordinarilybe sufhcient to, provide an airtight andwatertightspace. 1

A, runner R of this invention is shown in Fig. in combinationwith ausual type of hydraulic turbine construction having a radial inletprovided with any suitable flow control means such as wicket gates 31,an axial passage 32,.and draft tube. 33, the problem in connectionwithhydraulic turbines being peculiar thereto due to velocity conditions andother factors.

I As shown in'Fig. 16 the blade comprisesa bod-y having upper and lowerplates, the lower one 36 extending beyond the upper one as indicated at'3'? thereby forming a thin discharge edge portion consisting of'only asin- In .Fig.v the blade bodyd38 has its discharge edgeportion formedbya single plate I 39 secured preferablyto theunderside of the bedy whichis suitablyrecessed to receive the plate'and thereby provide smoothcontinuous upper andlower surfaces. -In either of the above formstheplates may bezsecured by welding as in any of the manners previouslyconsidered. Y .7 It is thus seen that from the constructions hereindescribed the blades are so formed and blade surface need be replacedwithout re placing-the remainder. Also, in the accomplishmentof'theseresults a very strong runner-blade is obtained with" the use of arelatively small amountofinetal, this being due to the utilization ofstructural beam principles which also apply to those forms showinFigsilQ to 14, as wellas to Fig. 6.

f f'l/vVhl-le the invention is illustrated and describedparticularlywith reference tor-unsners' -for hydraulic.turbinesandlpumps it is their upper and lower surfaces not confined thereto.butis intended to: cover anyotheruses or modifications; where a fluidtain meridian sections of said blade having their upper and lowersurfaces curved.

, 2, Arunner-for a turbine-or pump coniprising a hub ca ryingalloow-eblade, ce tain meridian sections .of said bl'ade, having theirupper-sand lower surfaces oppositely curved. i i

Arunner-for a turbine or.- pump. com-; pris ng a hub carrying a hollowblade, certain meridian sections of said bladeha-ving both con-'- cave.f 3' 41. A runner foraturbine orpuinp comprising a hub carrying a;hollow blade, certain meridian sections of said bladeLhaving upper andlower surfaces one of which is substantially straightand the otherconcave. 5. A-propeller type runner forv ahigh specific speed turbine orpump comprising a hub carrying hollow blades. the i opposite sides ofwhich comprise sheet metal plates, said plates being relativelyflat inthe direction in which fluid-normally flows thereover, while one of saidplates has-at least the major portion of its surface formed along 1substantially straight line-elements in meridian sections;

6;: A' propeller runnen-fo'r a high specific speedturbine "or pump Icomprisingahub carrying hollow blades, the oppositefaces of whichcomprisesheet metal plates, the upper one of said plates-having.straight line 7'. A propeller type runner for ahigh specific speedturbine or pump comprising a hub V carrying hollow blades each formed ofspaced sheet metal plates secured together attheir edges and beingrelativelyfl'at in meridian section, whilethe-upper plateisalsoflat-iathe directionin whichfiui'd' normally flow thereover.- 1 Y 8.;The combination in a high specific speed turbine, comprising.:apropeller type runner "having blades with a hollowv interior, .the

outer portionof'zeach blade being inclined: at

a small angle to the plane of runner rotation, means formingan entrancepassage. for conducting fillld' to said runnerandwhaving'provision forwhirling the infiowing-fluid, and a draft tube for" decelerating theflow: discharged from said runner :whereby'the back surfaces of therunner blades are-subjected to pressure. below atmosphere. 1 1

9. The combination in a high specific speed turbine, comprising apropeller type runner havingblades with a hollow'interior, the outerportion of said-blades in the directionof flow-thereover being disposedmore-nearly to the horizontal. than vertical, mean-s forming an entrancepassage for conducting fluid to said runner and having provision forwhirling the inflowing fluid, and a draft tube for decelerating the flowdischarged from said runner. whereby the back surfaces of the runnerblades are subjected to pressure below atmosphere, said runner beingformed of plate metal on the front and back sides.

10. The combination in a high specific speed turbine, com arising apropeller type runner having blades with. a hollow interior, the outerportion of said blades in the direction of flow thereover being disposedmore nearly to the horizontal than vertical, means forming an entrancepassage for conducting fluid to said runner and having provision forwhirling the inflowing fluid, and a draft tube for decelerating the flowdischarged from said runner whereby the back surfaces of the runnerblades are subjected to pressure below atmosphere, said runner havingblades at least one side of which is formed of plate metal.

11. The combination 7 in a high specific speed turbine, comprising apropeller type runner having blades with a hollow interior, the outerportion of said blades in the direction of flow thereover being disposedmore nearly to the horizontal than vertical, means forming an entrancepassage for conducting fluid to said runner and having provision forwhirling the inf-lowing fluid, and a draft tube for decelerating theflow discharged from said runner whereby the back surfaces of the runner blades are subjected to pressure below atmosphere, said runnerblades being formed of plate metal on the front and back sides which arewelded together along the entrance and discharge edges of the blade.

12. The combination in a high specific speed turbine, comprising apropeller type runner having blades with a hollow interior, meansforming an entrance passage for conducting fluid to said runner andhaving provision for whirling the inflowing fluid, and a draft tube fordecelerating the flow discharged from said runner whereby the backsurfaces of the runner blades are subjected to pressure belowatmosphere, said runner blades having plate metal on the front and backsides, the front side being relatively flat in the direction of thefluid flow thereover.

13. The combination in a high specific speed turbine, comprising apropeller type runner, having blades with a substantially hollowinterior, means forming an entrance passage for conducting fluid to saidrunner and having provision for whirling the inflowing fluid, and adraft tube for decelerating the flow discharged from said runner wherebythe back surfaces of the runner blades are subjected to pressure belowatmosphere, said runner blades having plate metal on the front and backsides, the front side being relatively flat while the back side hascurvature in the direction of the fluid flow thereover.

14:. The combination in a high specific speed hydraulic turbinecomprising a propeller type runner having a hub provided with lugsinclined with respect to the runner axis and extendingcircumferentially, upper and lower sheet metal plates spaced apart andsecured together adjacent their edges to form runner blades which aresecured 'to said lugs, means forming an entrance passage havingprovision for whirling the infiowing fluid to said runner, and a draft.tube for conducting the fluid discharged from said runner whereby theback sides of said blades are subjected to pressure below atmosphere.

15. The combination in a high specific speed turbine comprising apropeller type runner having blades which, in plan view, havesubstantially straight radial entrance and discharge edges extendingfrom substantially the blade tipto the hub, means forming an entrancepassage for conducting fluidto said runner and having provision forwhirling the inflowing fluid, and a draft tube for conducting the fluiddischarged from said runner, the front and back sides of said bladesbeing formed of sheet metal plates spaced apart to form a hollowinterior and secured together adjacent their edges.

16. A runner for a hydraulic turbine or pump comprising, a hub carryinga plurality of hollow blades the opposite sides of which comprise sheetmetal plates and, the combined peripheral edge portions thereofextending over a major extent of the runner periphery, said hub havingvane-shaped bosses integral therewith and to which the blade plates aresecured substantially throughout their complete contour at their hubends.

17. A propeller type runner for a high specific speed turbine or pumpcomprising a hub carrying a plurality of hollow blades, the oppositesides of which include sheet metal plates, said blades being relativelyflat in the direction in which fluid normally flows thereover and thecombined peripheral edge portions of said blades extending over a majorportion of the runner periphery, said plates when out in a section takenin the direction of flow having an entrance edge which is rounded fromface to back in a substantially continuous curve and a discharge endwhich is gradually tapered to a thin edge, the en trance portion of theblade being relatively thick and the discharge portion thereofrelatively thin.

18. A runner for a hydraulic turbine or pump comprising a hub carryinghollow blades, the opposite sides of which include sheet plates, saidhub having its outer contour formed as a surface of revolution havingsubstantially straight elements in neridian section.

$19. A runner i'fcr :a hydraulicturbine or pump comprising a hubcarrying hollow blades the'zcpposi'te sides of WhlCl'lfllIlCllldB sheetaplatespsaid :hub vhaving its outer "con- .tour 'formed as a surface ofrevolution having substantially straight elements in Y meridian section,the elements being inclined "-to the v runner lz'zxis thereby formingaaconical"hub. 20. A epropeller ltype runner for 1a 1 high specific speedturbinesompump comprising achub carrying hollow blades the oppositesides rof which comprise sheetimetal plates, said :platesibeing'yrel'atively flatin the direction in which I fluid: normally"flows 'therecver,

I IanrLsaidblades-alsochavingflan.axially-pro ieeted aarea substantiallyequal .to the. disc area between the hub andrunner -pe-riphery.LQLQAmunner for azhydnaulic turbine-cor pump comprising .a :hub.carrying hollow blades, the opposite I sidesof which. include sheet-metab plates spaced apart iadj acent the hub. and'rbreugliit:substantially graduallyttogeth'er' at: the-.di scharge and; peripheraledges 7 nftthe:bladesttherebyto provide melatively thin sections ofi'theblade adjacent :theperliphenalaandldischarge'edges;

. WLEWISJEERRYXMQODY.

